1. Field
The present disclosure relates generally to non-crimped fabrics and, in particular, to a method and apparatus for manufacturing low-bulk, non-crimped fabrics. Still more particularly, the present disclosure relates to a method and apparatus for creating composite materials from low-bulk, non-crimped fabrics.
2. Background
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Some aircraft may have more than 50 percent of their primary structure made from composite materials. Composite materials may be used in aircraft to decrease the weight of the aircraft. This decreased weight may improve payload capacities and fuel efficiencies. Further, composite materials may provide longer service life for various components in an aircraft.
Composite materials may be tough, lightweight materials created by combining two or more dissimilar components. For example, a composite material may include fibers and resins. The fibers and resins may be combined to form a cured composite material.
Further, by using composite materials, portions of an aircraft may be created in larger pieces or sections. For example, a fuselage in an aircraft may be created in cylindrical sections that may be put together to form the fuselage of the aircraft. Other examples may include, without limitation, wing sections joined to form a wing or stabilizer sections joined to form a stabilizer.
These composite components for aircraft may include composite materials such as, for example, without limitation, composite fabrics. The different components for an aircraft that may be created using composite materials include, for example, without limitation, a section of a fuselage, a wing panel, a wing rib, a spar, an aileron, a stabilizer, and other suitable components.
Currently used composite fabrics may be processed using a combination of heat, pressure, and vacuum in a tool, such as an autoclave. The particular part may be placed inside a bag in the autoclave. A vacuum may be applied to the bag to remove the air and volatile products. Heat and pressure may then be applied for curing. This type of process normally works well except, in some cases, a particular part may be too large for an autoclave or may require an expensive autoclave that is large enough to fit the part.
An alternative type of processing for composite components may be performed using manufacturing processes that do not require the use of an autoclave, such as those that use an oven. These types of processes may also be referred to as low-pressure molding processes.
Currently used processes for creating composite fabrics include, for example, using knitting machines that pull tows across an area and clamp those tows down at different orientations to make the desired fabric (e.g. U.S. Pat. No. 5,809,805). Tows are bundles of continuous fibers that are generally stored on spools and which are typically used to create the composite fabrics. An alternative to pulling tows across an area and clamping them down to produce fabrics may be to use pre-consolidated fabrics in which pick-and-place methods (e.g. U.S. Pat. No. 6,585,842) are employed to create these layers for the fabrics before they are knitted together.
These types of processes, however, may not have the desired quality, low bulk, or fiber spreading when producing composite components with low-pressure molding processes when an interlayer material is introduced between the plies. Accordingly, there is a need for a method and apparatus for minimizing inconsistencies in fabrics that overcomes the problems discussed above.